Solving
Equations

You
will get asked
to solve equations in your exam. Below are the types of
equations
you should study if your aiming for a C in maths.
Equations can crop up on either your calculator or non calculator paper
but they will probably turn up on both!

Example
Question

Solve:

a) 3(2x - 4) = 18
b) 2x + 14 = 2(2x - 3)

Solution

a)
To
solve equations we want to find the value of x. In other
words we
want x on its own the left hand side of the equation. To
achieve
this we need to use inverse operations.

3(2x - 4) = 18First expand the brackets to get:6x
- 12 = 18Now
to get rid of "-12" we add 12 to both sides which gives:6x
= 30Finally
remember "6x" means "6 times by x" so we divide both sides by 6:x
= 30 ÷ 6x
= 5

b)
Here we have a slightly harder example but the basic method stays the
same.

2x + 14 = 2(2x - 3)First expand the brackets to get:2x
+ 14 = 4x - 6Now
since we have x terms on both sides of the equation we write the
equation with the larger x term on the left:4x
- 6 = 2x + 14Now
we get rid of the smaller 2x term by subtracting 2x from both sides:2x
- 6 = 14Now
add 6 to both sides:
2x = 20
Finally divide both sides by 2 gives:
x = 10